Fabrication of lignocellulosic fiber–cement composite board and determination of optimum quantities of additives

Abstract

There is a growing desire to improve properties and use of nonwood plants as supplements to wood materials for wood fiber–cement boards. This study was conducted to determine the suitability of Equisetum telmateia fibers, fly ash (FA) and silica fume gel (SFG) as raw materials with high silica contents for manufacturing structural composite boards with target density and thickness of 1.10 g/cm3 and 13 mm respectively. Fibers were prepared and examined for their effects on Portland cement setting and its strength properties; moreover, FA and SFG were used to counteract the eventual adverse effects of fibers on the hydration properties of the cement matrix. All boards were tested for their thermal conductivity, physical and mechanical properties according to specification JIS standards. It was found that mechanical properties of fiber- cement boards were significantly improved by increasing Equisetum fibers, FA and SFG content, whereas thermal conductivity decreased. With regard to the physical properties, FA as cement replacement led to increase in WA and TS; however, SFG decreased mentioned properties. In general terms, the cement boards containing Equisetum fibers, FA and SFG exhibited superior physical, mechanical and thermal properties, which are important for structural applications, compared to the commercial products.